Yes they they are one of multiple pirates that charge for an old cloned copy of Open Source SumatraPDF code without opening up their mods. Some have added DRM or other “enhancements” and claimed their snake oil is better for protecting users “rights” but clearly breach licence rules themselves.
Some are reasonable translation forks to support other cultures and adhere to publishing their code on GitHub. However there are many more that rebadge or modify the interface and then claim their own copyright!
Avoid those that contain malware, or like UEB bundle other PUPs and use out of date libraries, or otherwise hit your pocket save yourself $29.99 and get the more secure free version here. https://www.sumatrapdfreader.org/prerelease.html
AFAIK There are only two “badged” official variants to SumatraPDF with slightly different behaviours one is the PortableApps version hosted on SourceForge see https://portableapps.com/apps/office/sumatra_pdf_portable#download_details the other is a trimmed down PDF variant you may note from the source code called “RA-MICRO PDF Viewer”